diff --git a/rust/source_provider.go b/rust/source_provider.go
index 4f8d22b..3236bce 100644
--- a/rust/source_provider.go
+++ b/rust/source_provider.go
@@ -31,9 +31,8 @@
 	Properties SourceProviderProperties
 
 	// The first file in OutputFiles must be the library entry point.
-	OutputFiles      android.Paths
-	subAndroidMkOnce map[SubAndroidMkProvider]bool
-	subName          string
+	OutputFiles android.Paths
+	subName     string
 }
 
 var _ SourceProvider = (*BaseSourceProvider)(nil)